It's hard to hide tattoos when you're a sexy celeb like Zoe Saldana! Skin-baring getups, after all, aren't the best at hiding your ink. But as it turns out, the 36-year-old mama-to-be is a regular Nick Wooster under those LBDs of hers, she admits in last night's interview on The Late Show.

On Zoe's August 2014 Women's Health cover, we can see a little hint of a tattoo under her arm — in a place that would normally be covered up. "I think people didn't realize — and how would they know? — that you have tattoos," asks host David Letterman. "Because in movies, they're covered."

"I'm running out of private places to put them on," she admits, adding that she has "almost 10" tattoos.

"My husband has more, but his are more exposed. But I have some on my stomach and stuff," she continues.

As it turns out, her devotion to body art doesn't stop at her own ink. "I am very proud to say I have assisted many friends and family, my sisters, to get tattoos," says the Avatar actress. "I get them drunk, I wine and dine them, I take them to the tattoo parlor, they come out with tattoos. The next day they're like, ‘What the hell happened?'"

The Guardians of the Galaxy actress, though, holds herself to a higher standard. "Whenever I go to get a tattoo, I'm actually very sober, for half of them," she clarifies, half-joking — we think. "I make a conscious decision. I go by myself."

Her most recent ink? "Heal" written in Hebrew, right in her under-boob region.

Despite a relatively modest, easily-coverable collection of tats, Grandma Saldana is still impressed. "My grandmother says I look like a newspaper naked. Because I have all these writings," says the Star Trek Into Darkness star. Oh, grandmas.

Watch the interview segment below!

Are you surprised that Zoe has ink, or would you be more shocked if she didn't? Let us know your thoughts in the comments!